1. Field of the Invention
The present invention relates to a hand-held power tool for at least percussively driving a working tool along a percussion axis and including a chuck, in particular, to hammer drill or chisel hammer.
2. Description of the Prior Art
Usually, in percussion hand-held power tools with an optionally rotatable, drive spindle, a chuck is secured on the spindle or, according to German Publication DE 37 20 512, is formed directly thereon.
In the chuck according to German Publication DE 37 20 512, a shank of a working tool, which is received in the receiving sleeve, has elongate locking grooves which are closed at both their axial sides and into which a radially displaceable locking member radially engages. The elongate locking grooves in cooperation with the locking member provide for a limited axial displacement of the working tool shank and, thereby, of the working tool. The shank is connected with the receiving sleeve for joint rotation therewith by axially and extending radially inwardly rotation-transmitting webs which are provided on the inner surface of the receiving sleeve and which engage in associated rotation-transmitting grooves provided on the shank. A percussion piston, which is driven by a pneumatic percussion mechanism applies blows to an axially displaceably supported anvil that, in turn, applies blows to the power tool side end surface of the shank.
European Publication EP 1 604 763 discloses a percussion hand-held power tool in which a one-piece pot-shaped anvil, which is open at its working tool side, is mounted on the drive spindle for joint rotation therewith and for a limited axial displacement relative thereto. The shank of the working tool is secured in the anvil again for joint rotation therewith and for a limited relative displacement relative thereto. The shank is flushed by a flushing liquid before the flushing liquid penetrates, at the end side, in the flushing bore of the working tool. The flushing fluid and seals, which are arranged between the movable parts, prevent penetration of abrasive dust to a most possible extent. This solution, which is optimal for a mining operation is not suitable for a dry standard use in the constructional industry.
U.S. Pat. No. 4,184,692 discloses a chuck of a power drill and connected with the drive spindle and in which a cylindrical shank of a drill, which is received in the chuck, is provided with a spherical dimple in which a radially displaceable locking ball engages for securing the shank and, thereby, the drill in the chuck against axial and rotational displacements relative to the chuck.
An object of the present invention is a percussion hand-held power tool having a chuck with which penetration of dust is prevented to a most possible extent.
Another object of the invention is a dust-tight chuck for a percussion hand-held power tool.
A further object of the present invention is to provide a working tool insertable in the inventive chuck.